Detailed re-analysis of satellitome mapping facilitated by the telomere-to-telomere (T2T) assembly of bread wheat genome.

The satellitome of Triticum aestivum cv. Chinese Spring consists of 36 satellite DNA (satDNA) families that were previously molecularly characterized and chromosomally mapped. The recent release of a complete gap-free telomere-to-telomere (T2T) assembly of the species offers a unique opportunity to refine the physical map and evolutionary interpretation of these sequences. Here, we re-evaluate the organization of the wheat satellitome by analyzing the T2T assembly with RepeatMasker and visualizing the results using the CHRISMAPP script. This research strengthens the notion that more than half of wheat satDNAs are connected to transposable elements (TEs) and enables us to propose a model of satDNA origin and evolution driven by TEs and other random genome sequences. By integrating T2T based physical mapping with previous FISH analyses, we refine the genomic distribution of tandem repeats, identify complex satellite organizations and length variants, and resolve several discrepancies between cytogenetic and genomic analyses. Finally, the detailed mapping of satDNA in centromeric and the subtelomeric regions highlight clear chromosome and subgenome specific patterns, suggesting potential roles of satellites in chromosome architecture. Together these findings provide the most complete and accurate satellitome map available for bread wheat, offering new insights into repeat evolution and genome organization in polyploid species.